Device for air cooling dustproof fan motors



June 26, 1923.

1,460,145 M. H. SPH-:LMAN

DEVICE FOR AIR COOLING DUSTPROOF1 FAN vMOTORS Filed Feb. 8, 1918 2 Sheets-Sheet l June 26, 1923.

M, H. SPIELMAN DEVICE FOR AIR COOLING DUSTPROOF FAN MOTORS S 1918 2 Sheets-Shed 2 Filed Feb.

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Patented June ze, 1923;

UNITED STATES MILTON I-I. SPELMAN, OF CLEVELAND, CHIC.

DEVICE FOB AIR COQLIING DUSTPRQGF FAN YEGTQRS. Y

Application filed February 8, 1918.

To all whom it may concern:

Be it known that I` MIUroN H. SPIELMAN, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful improvement in a Device for Air Cooling .Dustproof Fan Motors, of which the'following is a full, clear, and exa-ct description, reference being had to the accompanying drawings.

The purpose of this invention is to provide a simple and effective device for air cooling non-ventilated dust proof motors when used to drive fans or blowers, with the consequence that a much smaller motor may be used for a given result, thus greatly reducing the cost of such devices.

It has heretofore been the practice in a construction of motorsior driving,l fans, blowers or the like, where the atmosphere in which the motor is working is laden with foreign particles likelyr tointerfere with the effective operation of the motor or to injure its parts, to avoid suoli diiiiculties by entirely enclosing the motor in a thoroughly airtight casing. To so enclose a motor, however, renders it impractical to ventilate and cool the same by air passing through the interior thereof. Experience has demonstrated that the amount of air circulating around a motor is not ordinarily sufficient to cool a motor of a size otherwise suited to thel work to be done. Various expediente have been tried with a view to overcoming this difficulty, such for example as making a motor comparatively large with relation to the fan or running the motor at a low speed at which it is not so subject to overheating. In fact it has been necessary to use a closedmotor of twice the size. of a well ventilated motor otherwise adapted for the work. By the use of my invention ll may accomplish the moving of the desired volume of air with a comparatively small and much cheaper motor, and may attach the fan directly to the arma-ture shaft, which is very desirable, and still accomplish the cooling of the motor to a temperature at which it may run safely and efficiently.

My method of accomplishing the 'above results is illustrated in a convenient embodiment shown in the drawings hereof and the essential characteristics of this invention are summarized in the claims.

In the drawings, Fig. 1 is a vertical substantially axial section through a blower casing showing the fan therein and the Y Serial No. 216,141.

ary housing surrounding the motor shoarma;

the method of securing Ithe motor in tion.

Describing the parts by the use ci' ence numerals, i and 2 indicate the side w members orn a Yfan chamber 'for a blower substantially the usual construction a formed 'to provide an air outlet at 3, two side wall members being secured gether in the usual manner by bolts through ears 5. The blower chamber w member 2 is provided with the compara tively large central opening into which itted the inner end of subst/ainsiallT cylindrical housing' 10 provided with a flange il fitting a raised portion en thewell 2' and secured thereto by screws l2.

This cylindrical housing extends outwardly from the wall 2 'for a considerable distance and contains e motor 20 havingl an armature sh ait 2l on which may be mount-ed a ian. 252 of any suitable construction. shown the jfan has a comparatively staan hub 23 from which radiate the intefrrel blades braced by an integral disk high speed motor and is preferably provided with a substantially cylindrical cas ing. l' prefer to mount the motor in the casing in a manner which will oder the least resistance to air passing through the` annu lar passage around the motor, and .accord ingly l provide hollow distance bloc-ks Sti. between the housing` l() and suitable bosse on the wall of the motor, and through thee` distance blocks extend screws 3l 'passing through the housing; l0 and threaded El into the motor casing.

rlhere are preferably four 4ot these dis tance blocks and securing screws, arranged two on each side of the center at the lower side of the motor.

rllhe leed wires B5 preferably lead through an insulating tube 36 extending through opening in the housing 10 to the motor ing, as shown.

The inner end oi the cylindrical housinm l0 is provided with en integral inwar ills n i ne motor 2O illustrated is a small l* till tee

'preferably turned flan 15, sloping` somewhat toward the fan, a shown as eaving an opening vlil for the of air, which opening is portion of the fan wheel within the bracingp ring 24. The flange 15 serves the dual function of causing the air to be forced into close contact with the inner end of the motor and armature shaft as well as directin it properly to the central portion of the an. This feature is important for the reason that the cooling of the parts at the inner end of the motor has the effect of absorbing the heat traveling along them from the interior of the motor. The area of the passage around the motor has a definite relation to the area of the opening within the flange.. (lwing'` to frictional losses the area of the passage is preferably slightly larger than that of this opening. The surface of the motor casing within the housing is determined accord.- ing to the amount of air passing over it necessary'to obtain a proper working temperature, and may be changed bymvarying the length of the housing 10.

The proportions shown in the drawings have been taken from a device embodying my invention, which device has been in pracJ tical use for suicient length of time to demonstrate the praeticability and utility of :incense this invention. A small high speed entirely enclosed motor is used and a fan relatively small in proportion to the 'volume of air to be discharged, the motor and fan being run at a high speed, and yet the motor remains at a proper low temperature suitable to efective operation and with no danger of injurj,7 from overheating,

` Having thus described my invention, what I claim is 1. In combination, a motor having a pro- .jeoting armature shaft, an airtight casing surrounding the motor and from which the armature shaft projects, a fan on the armature shaft, a. tubular casing surrounding the airtight motor casing, the end of the casing adjacent the fan having an inwardly eX- tending flange,'and a housing secured to the second mentioned casing and surrounding the fan, a tangential outlet in the housing to provide a blower, said tubular casing iitting Within the housing, said flange deining -a central opening to the fan for all the air passing through the blower.

2.y A fan blower comprising a fan housing having a single centrally positioned entrance opening, a sleeve extending from said entrance opening, said sleeve having a flange thereon inwardl turned toward the fan, and a nonL venti ated motor in said sleeve, said motor havincr an airtight casing supported within sai sleeve in spaced relation thereto and having an armature shaft projecting through the entrance opening into the fan housing, a fan fixed on said shaft whereby all the air supplied to the fan passes around said motor andl through the restricted opening defined by the flange.

In testimony whereof, I hereunto aix my signature.

MHJTON H. iiPIEIMAN. 

